1. Field of the Invention
The present invention relates to an ink supplying system such as an ink cartridge, a connection unit, etc., for supplying ink to an ink jet recording head that ejects ink droplets in response to a print signal. The present invention also relates to a recording apparatus using such an ink supplying system.
2. Related Art
In a recording apparatus of the type in which ink is supplied to an ink jet recording head from an ink cartridge that is detachably mounted on a carriage having the recording head thereon, the cartridge is constructed such that the ink is filled in a flexible ink bag and the ink bag is accommodated in a hard case as disclosed, for example, in Europe Patent No.562717.
Since the ink cartridge thus constructed has no porous member, the ink cartridge can efficiently utilize the container volume of the ink cartridge to accommodate a large quantity of ink, thereby improving the ratio of the ink quantity per the container volume in comparison to an ink cartridge having the ink impregnated in a porous member.
However, since the ink is not held under a capillary force of the porous member, a liquid column of the accommodated ink directly acts on the recording head to change the ink pressure on the recording head depending on a change in quantity of ink. Further, pressure fluctuation acts on the recording head, which is caused by motion of the ink due to the reciprocal movement of the carriage. Consequently, the print quality is degraded.
An ink cartridge for an ink jet recording apparatus, provided according to the present invention, comprises:
a flexible ink bag storing ink therein and having an ink flow port;
a case member storing the ink bag therein;
an ink supply port which supplies ink in the ink bag to a recording head; and
a negative pressure generating system which is provided between the ink flow port and the ink supply port, and which maintains pressure of the ink supply port to be lower by a specified value than pressure in the ink bag.
Another ink cartridge for an ink jet recording apparatus, provided according to the present invention, comprises:
an ink storing chamber;
an atmosphere communicating connection port communicated with the ink storing chamber, and maintaining a closed condition in a first state in which the ink cartridge is not attached on a recording apparatus;
an ink supplying connection port communicated with the ink storing chamber, and maintaining a closed condition in the first state; and
a negative pressure generating system which supplies ink to the ink supplying connection port while maintaining a predetermined negative pressure state.
Yet another ink cartridge for an ink jet recording apparatus, provided according to the present invention, comprises:
an ink storing chamber;
an atmosphere communicating connection port communicated with the ink storing chamber, and maintaining a closed condition in a first state in which the ink cartridge is not attached to the recording apparatus; and
an ink supplying connection port communicated with the ink storing chamber, and maintaining a closed condition in the first state,
wherein ink is supplied from the ink cartridge to a recording head via a connection unit that has a negative pressure generating system and that is provided to the recording apparatus.
Accordingly, it is a first object of the invention to provide an ink cartridge that can supply ink to a recording head at a pressure as constant as possible regardless of change in ink quantity and movement of a carriage.
It is a second object of the invention to provide an connection unit that connects an ink cartridge to a recording head and that can supply ink to a recording head at a pressure as constant as possible to a recording head regardless of change in ink quantity and movement of a carriage.
It is a third object of the invention to provide a recording apparatus employing the ink cartridge and/or the connection unit.
The present disclosure relates to the subject matter contained in Japanese patent application Nos.:
2000-37410 (filed on Feb. 16, 2000);
2000-85989 (filed on Mar. 27, 2000);
2000-85791 (filed on Mar. 27, 2000);
2000-86007 (filed on Mar. 27, 2000);
2000-92802 (filed on Mar. 30, 2000);
2000-229167 (filed on Jul. 28, 2000);
2000-228542 (filed on Jul. 28, 2000); and
2000-229166 (filed on Jul. 28, 2000),
which are expressly incorporated herein by reference in their entireties.